CA2109536A1 - Filter assembly having a filter element and a sealing device - Google Patents
Filter assembly having a filter element and a sealing deviceInfo
- Publication number
- CA2109536A1 CA2109536A1 CA002109536A CA2109536A CA2109536A1 CA 2109536 A1 CA2109536 A1 CA 2109536A1 CA 002109536 A CA002109536 A CA 002109536A CA 2109536 A CA2109536 A CA 2109536A CA 2109536 A1 CA2109536 A1 CA 2109536A1
- Authority
- CA
- Canada
- Prior art keywords
- sealing device
- filter element
- filter
- filter assembly
- compressible material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000007789 sealing Methods 0.000 title claims abstract description 81
- 239000000463 material Substances 0.000 claims abstract description 42
- 239000012530 fluid Substances 0.000 claims description 21
- 239000000919 ceramic Substances 0.000 claims description 20
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 11
- 239000000835 fiber Substances 0.000 claims description 2
- 230000002093 peripheral effect Effects 0.000 claims 2
- 238000004140 cleaning Methods 0.000 description 10
- 230000008901 benefit Effects 0.000 description 7
- 230000007246 mechanism Effects 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 239000007789 gas Substances 0.000 description 6
- 230000036316 preload Effects 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 230000002441 reversible effect Effects 0.000 description 5
- 230000035939 shock Effects 0.000 description 5
- 229910010293 ceramic material Inorganic materials 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 229910001092 metal group alloy Inorganic materials 0.000 description 4
- 238000003754 machining Methods 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000001351 cycling effect Effects 0.000 description 2
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229910052863 mullite Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910000323 aluminium silicate Inorganic materials 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 229910052729 chemical element Inorganic materials 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000000462 isostatic pressing Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000010297 mechanical methods and process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/0002—Casings; Housings; Frame constructions
- B01D46/0005—Mounting of filtering elements within casings, housings or frames
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
- B01D29/31—Self-supporting filtering elements
- B01D29/33—Self-supporting filtering elements arranged for inward flow filtration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/50—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition
- B01D29/52—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in parallel connection
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/62—Regenerating the filter material in the filter
- B01D29/66—Regenerating the filter material in the filter by flushing, e.g. counter-current air-bumps
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
- B01D29/88—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor having feed or discharge devices
- B01D29/92—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor having feed or discharge devices for discharging filtrate
- B01D29/925—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor having feed or discharge devices for discharging filtrate containing liquid displacement elements or cores
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
- B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
- B01D46/2407—Filter candles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/42—Auxiliary equipment or operation thereof
- B01D46/4281—Venturi's or systems showing a venturi effect
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/56—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with multiple filtering elements, characterised by their mutual disposition
- B01D46/58—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with multiple filtering elements, characterised by their mutual disposition connected in parallel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2201/00—Details relating to filtering apparatus
- B01D2201/04—Supports for the filtering elements
- B01D2201/043—Filter tubes connected to plates
- B01D2201/0446—Filter tubes connected to plates suspended from plates at the upper side of the filter elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2201/00—Details relating to filtering apparatus
- B01D2201/34—Seals or gaskets for filtering elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2271/00—Sealings for filters specially adapted for separating dispersed particles from gases or vapours
- B01D2271/02—Gaskets, sealings
- B01D2271/022—Axial sealings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2271/00—Sealings for filters specially adapted for separating dispersed particles from gases or vapours
- B01D2271/02—Gaskets, sealings
- B01D2271/027—Radial sealings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2273/00—Operation of filters specially adapted for separating dispersed particles from gases or vapours
- B01D2273/20—High temperature filtration
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Filtering Of Dispersed Particles In Gases (AREA)
- Filtering Materials (AREA)
Abstract
ABSTRACT:
The present invention provides a filter assembly including a sealing device having first and second surfaces. A filter element has a first surface disposed about the first surface of the sealing device. The filter element has a second surfaces disposed adjacent to the second surface of the sealing device. A compressible material is disposed between the first surface of the filter element and the first surface of the sealing device and between the second surface of the filter element and the second surface of the sealing device. The filter element has a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the sealing device. The compressible material is compressed between the second surfaces at a first predetermined temperature. The differing coefficients of thermal expansion combine with an increase in temperature of the filter assembly to a second predetermined temperature, higher than the first predetermined temperature, to compress the compressible material between the first surfaces. Thus a effective seal is formed at both the first and second predetermined temperatures.
The present invention provides a filter assembly including a sealing device having first and second surfaces. A filter element has a first surface disposed about the first surface of the sealing device. The filter element has a second surfaces disposed adjacent to the second surface of the sealing device. A compressible material is disposed between the first surface of the filter element and the first surface of the sealing device and between the second surface of the filter element and the second surface of the sealing device. The filter element has a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the sealing device. The compressible material is compressed between the second surfaces at a first predetermined temperature. The differing coefficients of thermal expansion combine with an increase in temperature of the filter assembly to a second predetermined temperature, higher than the first predetermined temperature, to compress the compressible material between the first surfaces. Thus a effective seal is formed at both the first and second predetermined temperatures.
Description
~`~
A FILTER ASSEMBLY HAVING A
FILTER ELEMEN~ AND A SEALING PEVICE
I The present invention relates to filter assem-I blies which ~ay be used, for example, to remove particulates from high temperature fluids.
Tube type f~lter are typically used in indus-trial processes for purifying fluidis in either the - ga~eous or liquid phase. Typical applications in-clude, but are not li~ited to, coal ga~ifiers, fluidiz~d bed combustors, smelters, and catalytic crackers.
As disclosed in United States Patent 4,725,356, conventional tube-type filters generally comprise a tank or pressure ve~sel which is divided into an inlet portion and an outlet portion by a relatively I rigid support member called a tube sheet. The tube ¦ sheet preferably forms a fluid tight seal between the inlet portion and the outlet portion and typi-cally has a series of holes or apertures spaced from one another. Filter element~ are mounted in the apertures of the tube sheet.
I One type of conventional filter element is made of a porous ceramic material and is commonly re-ferred to a~ a candle filter. Candle ~ilters are part$cularly effective in removing particulates from high pre sure, high temperature gases. A candle filter typically comprise~ a hollow, cylindrical tube that may have a narrow, elongated cross sec-tion, for example, a diameter in the range of 5-30 17cm, and a length in the range of 0.1-3.0 m. The hollow tube typically has one end which is closed, one end which is open, and a porous, ceramic side wall. The porous side wall extends between the ends of the tube and defines an internal cavity that opens at the open end of the tube. The open end of the tube usually has a flange.
In a typical arrangement, one or more filter elements are arranged vertically inside the tank.
Each filter element is inserted through an aperture in the tube sheet and is normally positioned such that the porous side wall and the closed end are located in the inlet portion of the tank while the flange of the tube i8 mounted to the tube ~heet with the open end of the filter element communicating with the outlet portion of the tank. The flange has a larger diameter than the ~ide wall of the filter element and allows the filter element to be located in and suspended by the tube sheet. A gasket mate-rial may be disposed between the flange and the tube sheet to form a seal and prevent bypass of unfil-tered proce~s fluid. A mechanism for clamping the 20 f ilter elements againct the tube sheet to secure the filter elements in position and maintain the seal is also provided.
With the filter elements mounted in place, a fluid, ~uch as a gas laden with particulates, is 2 5 introduced into the inlet portion of the ta~k. From the inlet portion, the gas passes through the porous wall of each filter element, where the particulates are removed from the gas, and into the internal cavity. The filtered gas then passes axially along - 30 the internal cavity of the filter elements and into the outlet portion of the tank through the open ends of the filter elements before exiting the tank through the outlet portion~ As the fluid passes through the porous walls of the filter elements, particulates accumulate on the upstream side of the : .
-- 2 -- ~
. . - .: ~: . - ,: :
filter elements. with time, the particulates build up on the upstream side and form a particulate cake.
The build-up of the particulate cake prevents fluid - flow and, therefore, creates the need for the filter ;~ 5 elements ts be cleaned or replaced periodically.
One particularly effective method of cleaning the filter elements is by using a high pressure reverse gas flow. For example, cleaning may be accomplished by mounting a reverse cleaning fluid nozzle in close proximity to the op~n end of the filter element. A high pressure fluid (e.g., inert gas, air, or steam) is injected into the filter element in the reverse direction of normal fluid flow. The high pressure cleaning fluid is rapidly turned on and off to create a high pressure pulse in the back flow direction, dislodging the particulate cake formed on the upstream side of the filter elements.
Unfortunately, conventional tube-type filters are su~ceptible to a number of problems. Stress from improper clamping, mechanical vibrations, un-even contours on the filter surface or support, and thermal shock may result in damage to the filter element or leakage through the gasket. Back flow cleaning may introduce thermal shock to the filter elements if the high pressure reverse flow fluid is not at the same temperature as the filter elements.
In addition, the use of a high pressure back flow cleaning pulse generates vibrations and mechanical stress on the filter elements. In candle filt0rs, a common failure mode is cracking at the flange due to stress.
In addition, the tube sheet and the clamping mechanism are typically constructed using a metal alloy, while the filter element is typically ~ ~ u ~ ~ 3 S
.
~.' - construed of a ceramic material. Bec~use ceramics typically have a much lswer thermal coefficient of i expansion than metal alloys, the ceramic filter elements and the metal tube sheet and clamping j 5 mechanism may expand at different rates due to temperature changes. These differing rates of thermal expansion can result in a reduction of the ~J clamping force and leakage past the seal.
~ Accordingly, the present invention provides a ~ 10 filter assembly comprising: a seali~lg device having j first and second surfaces; a filter element having ~, first and second surfaces respectively disposed about the first ~ur~ace of the sealing device and ad~acent to the second surface of the sealing device; and a compressible material respectively disposed between the first and ~econd surfaces of the filter element and the fir~t and s~cond surfaces !- of the sealing device, wherein the filter element has a coef~icient of thermal expansion that differs from the coefficient of thermal expansion of the sealing device, the compressible material being compressed between the second surfaces at a first predetermined temperature, and the differing ¦ coefficients of thermal expansion combine with an 1 25 increase in temperature of the filter assembly to a second predetermined temperature, higher than the ¦ first predetermined temperature, to compres~ the I compressible material between the first surfaaes, for forming a seal at both the first and second predetermined temperatures.
The present invention also provides a filte~r asse~bly comprising: filter assembly comprising: a filter element having a porous ceramic tube having an open end and a flange including an annular groove, and an annular metal sealing deviae disposed " ', l V ~
within the annular groove having a first surface.
~ Embodiments of the present invention thus use '~ an entirely different mechanism from the convention-, al devices to maintain a seal: the ~ealing device j 5 and the filter element may have different ', coefficients of thermal expansion and these different coefficients of thermal expansion may be used advantageously to increase the reliability, effectiveness, and efficiency of a seal. A
10 principal advantage of the present invention is that a filter element i8 efectively sealed within a ~-, filter a sembly.
Another principal advantage of the present invention is that the stress at the flange of the i 15 filter element i5 greatly red~ced.
Additional advantages of the present invention include sealing the filter element throughout the entire range of operating temperature of the filter ~ assembly: providing multiple sealing ~urfaces to j 20 enhance reliability; providing a ~ealing mechanism ~ which also functions to increase the efficiency of ¦ back flow cleaning.
~ Figure 1 is a sectional view of a first 3 embodiment of a filter assembly device according to ~ 25 the present invention:
j~ Figure 2 is a sectional view showing the de-tails of the sealing device employed in the filter assembly of Figure 1:
, Figure 3A is a top view of the sealing device ii, 30 of ~igure 2:
Figure 3B is a side view of the sealing device of Figure 3A;
Figure 4 is a sectional view of a second , :
,. . .
`, ' . ~ ! .
r"~ " , r,~
' ' "
~ ~'JJ~i 3 1~
em~odiment of a filter assembly according to the ' present invention; and Figure 5 is a sectional view showing details of a third e~bodi~ent of a filter assembly according to the present invention.
, Referring to Figure 1, a first exemplary filter assembly 1 embodying the present invention generally comprises a pressure tank 2, a rigid sheet or tube sheet 3 extending across the interior of the tank, one or more filter element 4 disposed within the tank 2, and one or more sealing devices 5 for ~ ~ealing the filter elements 4 to the tube sheet 3.
¦ An inlet portion 6 of the pre~sure tank 2 may be sealed from an outlet portion 7 of the pressure tank 2 by the tube sheet 3. An inlet 8 may be coupled to ~ the inlet portion 6 for providing a fluid to the ¦ filter a~se~bly 1. An outlet 9 may be coupled to ¦ the outlet portion 7 for removing the fluid once it ! has passed through the filter elements 4. optional-ly, a back flow cleaning system (not shown) can be provided for supplying a hig~ pressure fluid in the ~ reverse direction for cleaning the filter elements 4 i and a cooling system (not shown) including coolant tubes can be provided in the tube sheet to maintain ¦ 25 the temperature of the tube sheet below a ¦ predetermined value.
; Each filter element 4 is preferably narrow and elongated. It may include a closed or blind end, an open end, and a porous side wall. The side wall extends from the closed end to the open end and has an internal surface which defines a cavity that opens at the open end. The filter element 4 is preferably a filter constructed of a porous ceramic.
The ceramic may be made of ~uch compositions as Si3N4, mullite, cordierite (MgO, Al203, sio2~, ~,., .~ . .
,. : :
~ r~
e) t3 fireclay, aluminosilicate fibers, alumina, alumi-na/mullite, and ~ilicon carbi~e-based materials. In a preferred embodiment, a hollow, porous, ceramic candle filter is used as the filter element 4.
Figure 2 illustrates a sectional view of the details of the location of the filter element 4 in the tube sheet 3 of a first embodiment of the filter asse~bly 1 of Figure 1. In this embodiment, the filter element 4 is slidably inserted from the upper side of the tube sheet 3 through a hole or aperture 11 in t~e tube sheet 3. The open end of the filter element 4 may include a flan~e 12 which prevents the filter element 4 from passing completely through the aperture 11. The flange 12 may be at any suitable angle to an axis 28 of the filter element 4. If the flange is at a right angle, the flange may engage the top of the tube sheet 3 or a lip formed in the wall defining the aperture 11. In the first embodiment, the flange 12 slopeæ upwardly at an acute angle and cooperates with a corresponding locating profile 13, e.g., an annular bevel, in the aperture wall.
In accordance with one aspect of the invention, a sealing device 5 i8 preferably utilized to seal the filter element 4 to the tube sheet 3. In the first embodiment, the ~ealing device 5 also functions as a hold-down element for securing each filter element 4 to the tube sheet 3. The sealing device 5 may be fabricated as a ~ingle unitary piece or from two or more separate sections by, for example, machining, forming, stamping, or casting.
If it is made from two or more separate sections, the sections of the sealing ~evice 5 may be joined together by various methods ~uch as a welded, threaded, or press fit connection. Further, the ~ ~ U~3~
sealing device 5 may be variously configured without departing from the ~cope of the invention. For example, the illustrated sealing device 5, as shown in Figures 3-4, may include a ~lat planar or disk section 15 and a hollow cylindrical section 16 which are unitarily formed. In a preferred embodiment, it may be defiirable for a planar bottom surface of the disk ~ection 15 to have a larger diameter than the ~ cylindrical section ~6 and extend radially out be-¦ 10 yond an outer surface 21 of the hollow cylindrical section 16, forming the bottom annular surface 20.
The sealing device 5 includes an internal passage 19 passing through the device from one open end to another. For example, in the illustrated sealing device 5, the passage 19 extends axially ~ through the hollow cylindrical sectisn 16 and ¦ through the planar surface of the disk section 15.
The configuration of the internal passage 19 may or may not be arranged in such a manner as to act a~ a 20 venturi or nozzle 17. The nozzle 17, or an alterna-tive capillary (jet) configuration, can be used to ~ increase the velocity of fluid flowing in the back ¦ flow direction and, thus, to enhance the blowback effectiveness when the filter elements 4 are cleaned. In an alternative embodiment, it my he preferable for the internal passage 19 to be config-ured as a plurality of internal passages. At least one of th~se plurality of internal passages may be formed into a nozzle, capillary, or jet configura- -tion to provide a means for increasing back flow efficiency. In yet another embodiment, the internal passage may simply be a cylindrical bore.
Chemical corrosion may occur as ~ result of chemicals in the fluids processed through the filter assembly. As a result, the sealing device S is ~;, , . , . . , ................. , . , ~
~', ' ' , , . . . '.' ~'~: ' ' , ; ' ,.'.''. , ~ L U ~ ~ 3 g preferably manufactured from a material which resists corrosion, for example, a high temperature, corrosion resistant, metal alloy such as RA333, available from Rolled Alloys of Temperance, MI.
The sealing device 5 is shown in Figure 2 as it might appear installed in a filter assembly 1.
The sealing device 5 is placed over the top of the filter element 4 with the hollow cylindrical ~ection 1 16 extending for some distance into the internal : lO cavity of the filter element 4. For example, the cylindrical section 16 of the sealing device 5 may '` extend into the internal cavity of the filter f element 4 a distance at least a~ great as the thickness of the tube sheet 3. It may be desirable 15 to position a compressible cu~hioning and/or sealing ~ material 14 between the filter element 4 and the f tube ~heet 3 and/or between the sealing device 5 and I the filter element 4. In a preferred embodiment, ! the compressible material 14 may be a high ~ 20 temperature gasket material, most preferably a ¦ ceramic fiber material such as that available from ¦ 3M Corporation under the trade designation Interam.
i In the illustrated embodiment, the compressible material 14 is disposed between the filter element 4 25 and the tube sheet 3 only at the portion of the tube sheet forming the locating profile 13. Of course, it i8 possible to have the compressible material 14 located over the entire area between the filter element 4 and the tube sheet 3. The openings in the 30 tube sheet 3 may have portions that closely match the profile of the outer portion of the filter ele-ment 4 and, in particular, the flange 12. The comp-ressible material 14 placed between the tube sheet and the filter ele~ent 4 acts to dampen any vibra-35 tion which may be transferred to the filter element _ g _ ~,: . . , - , : , , 3 ~
A FILTER ASSEMBLY HAVING A
FILTER ELEMEN~ AND A SEALING PEVICE
I The present invention relates to filter assem-I blies which ~ay be used, for example, to remove particulates from high temperature fluids.
Tube type f~lter are typically used in indus-trial processes for purifying fluidis in either the - ga~eous or liquid phase. Typical applications in-clude, but are not li~ited to, coal ga~ifiers, fluidiz~d bed combustors, smelters, and catalytic crackers.
As disclosed in United States Patent 4,725,356, conventional tube-type filters generally comprise a tank or pressure ve~sel which is divided into an inlet portion and an outlet portion by a relatively I rigid support member called a tube sheet. The tube ¦ sheet preferably forms a fluid tight seal between the inlet portion and the outlet portion and typi-cally has a series of holes or apertures spaced from one another. Filter element~ are mounted in the apertures of the tube sheet.
I One type of conventional filter element is made of a porous ceramic material and is commonly re-ferred to a~ a candle filter. Candle ~ilters are part$cularly effective in removing particulates from high pre sure, high temperature gases. A candle filter typically comprise~ a hollow, cylindrical tube that may have a narrow, elongated cross sec-tion, for example, a diameter in the range of 5-30 17cm, and a length in the range of 0.1-3.0 m. The hollow tube typically has one end which is closed, one end which is open, and a porous, ceramic side wall. The porous side wall extends between the ends of the tube and defines an internal cavity that opens at the open end of the tube. The open end of the tube usually has a flange.
In a typical arrangement, one or more filter elements are arranged vertically inside the tank.
Each filter element is inserted through an aperture in the tube sheet and is normally positioned such that the porous side wall and the closed end are located in the inlet portion of the tank while the flange of the tube i8 mounted to the tube ~heet with the open end of the filter element communicating with the outlet portion of the tank. The flange has a larger diameter than the ~ide wall of the filter element and allows the filter element to be located in and suspended by the tube sheet. A gasket mate-rial may be disposed between the flange and the tube sheet to form a seal and prevent bypass of unfil-tered proce~s fluid. A mechanism for clamping the 20 f ilter elements againct the tube sheet to secure the filter elements in position and maintain the seal is also provided.
With the filter elements mounted in place, a fluid, ~uch as a gas laden with particulates, is 2 5 introduced into the inlet portion of the ta~k. From the inlet portion, the gas passes through the porous wall of each filter element, where the particulates are removed from the gas, and into the internal cavity. The filtered gas then passes axially along - 30 the internal cavity of the filter elements and into the outlet portion of the tank through the open ends of the filter elements before exiting the tank through the outlet portion~ As the fluid passes through the porous walls of the filter elements, particulates accumulate on the upstream side of the : .
-- 2 -- ~
. . - .: ~: . - ,: :
filter elements. with time, the particulates build up on the upstream side and form a particulate cake.
The build-up of the particulate cake prevents fluid - flow and, therefore, creates the need for the filter ;~ 5 elements ts be cleaned or replaced periodically.
One particularly effective method of cleaning the filter elements is by using a high pressure reverse gas flow. For example, cleaning may be accomplished by mounting a reverse cleaning fluid nozzle in close proximity to the op~n end of the filter element. A high pressure fluid (e.g., inert gas, air, or steam) is injected into the filter element in the reverse direction of normal fluid flow. The high pressure cleaning fluid is rapidly turned on and off to create a high pressure pulse in the back flow direction, dislodging the particulate cake formed on the upstream side of the filter elements.
Unfortunately, conventional tube-type filters are su~ceptible to a number of problems. Stress from improper clamping, mechanical vibrations, un-even contours on the filter surface or support, and thermal shock may result in damage to the filter element or leakage through the gasket. Back flow cleaning may introduce thermal shock to the filter elements if the high pressure reverse flow fluid is not at the same temperature as the filter elements.
In addition, the use of a high pressure back flow cleaning pulse generates vibrations and mechanical stress on the filter elements. In candle filt0rs, a common failure mode is cracking at the flange due to stress.
In addition, the tube sheet and the clamping mechanism are typically constructed using a metal alloy, while the filter element is typically ~ ~ u ~ ~ 3 S
.
~.' - construed of a ceramic material. Bec~use ceramics typically have a much lswer thermal coefficient of i expansion than metal alloys, the ceramic filter elements and the metal tube sheet and clamping j 5 mechanism may expand at different rates due to temperature changes. These differing rates of thermal expansion can result in a reduction of the ~J clamping force and leakage past the seal.
~ Accordingly, the present invention provides a ~ 10 filter assembly comprising: a seali~lg device having j first and second surfaces; a filter element having ~, first and second surfaces respectively disposed about the first ~ur~ace of the sealing device and ad~acent to the second surface of the sealing device; and a compressible material respectively disposed between the first and ~econd surfaces of the filter element and the fir~t and s~cond surfaces !- of the sealing device, wherein the filter element has a coef~icient of thermal expansion that differs from the coefficient of thermal expansion of the sealing device, the compressible material being compressed between the second surfaces at a first predetermined temperature, and the differing ¦ coefficients of thermal expansion combine with an 1 25 increase in temperature of the filter assembly to a second predetermined temperature, higher than the ¦ first predetermined temperature, to compres~ the I compressible material between the first surfaaes, for forming a seal at both the first and second predetermined temperatures.
The present invention also provides a filte~r asse~bly comprising: filter assembly comprising: a filter element having a porous ceramic tube having an open end and a flange including an annular groove, and an annular metal sealing deviae disposed " ', l V ~
within the annular groove having a first surface.
~ Embodiments of the present invention thus use '~ an entirely different mechanism from the convention-, al devices to maintain a seal: the ~ealing device j 5 and the filter element may have different ', coefficients of thermal expansion and these different coefficients of thermal expansion may be used advantageously to increase the reliability, effectiveness, and efficiency of a seal. A
10 principal advantage of the present invention is that a filter element i8 efectively sealed within a ~-, filter a sembly.
Another principal advantage of the present invention is that the stress at the flange of the i 15 filter element i5 greatly red~ced.
Additional advantages of the present invention include sealing the filter element throughout the entire range of operating temperature of the filter ~ assembly: providing multiple sealing ~urfaces to j 20 enhance reliability; providing a ~ealing mechanism ~ which also functions to increase the efficiency of ¦ back flow cleaning.
~ Figure 1 is a sectional view of a first 3 embodiment of a filter assembly device according to ~ 25 the present invention:
j~ Figure 2 is a sectional view showing the de-tails of the sealing device employed in the filter assembly of Figure 1:
, Figure 3A is a top view of the sealing device ii, 30 of ~igure 2:
Figure 3B is a side view of the sealing device of Figure 3A;
Figure 4 is a sectional view of a second , :
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em~odiment of a filter assembly according to the ' present invention; and Figure 5 is a sectional view showing details of a third e~bodi~ent of a filter assembly according to the present invention.
, Referring to Figure 1, a first exemplary filter assembly 1 embodying the present invention generally comprises a pressure tank 2, a rigid sheet or tube sheet 3 extending across the interior of the tank, one or more filter element 4 disposed within the tank 2, and one or more sealing devices 5 for ~ ~ealing the filter elements 4 to the tube sheet 3.
¦ An inlet portion 6 of the pre~sure tank 2 may be sealed from an outlet portion 7 of the pressure tank 2 by the tube sheet 3. An inlet 8 may be coupled to ~ the inlet portion 6 for providing a fluid to the ¦ filter a~se~bly 1. An outlet 9 may be coupled to ¦ the outlet portion 7 for removing the fluid once it ! has passed through the filter elements 4. optional-ly, a back flow cleaning system (not shown) can be provided for supplying a hig~ pressure fluid in the ~ reverse direction for cleaning the filter elements 4 i and a cooling system (not shown) including coolant tubes can be provided in the tube sheet to maintain ¦ 25 the temperature of the tube sheet below a ¦ predetermined value.
; Each filter element 4 is preferably narrow and elongated. It may include a closed or blind end, an open end, and a porous side wall. The side wall extends from the closed end to the open end and has an internal surface which defines a cavity that opens at the open end. The filter element 4 is preferably a filter constructed of a porous ceramic.
The ceramic may be made of ~uch compositions as Si3N4, mullite, cordierite (MgO, Al203, sio2~, ~,., .~ . .
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e) t3 fireclay, aluminosilicate fibers, alumina, alumi-na/mullite, and ~ilicon carbi~e-based materials. In a preferred embodiment, a hollow, porous, ceramic candle filter is used as the filter element 4.
Figure 2 illustrates a sectional view of the details of the location of the filter element 4 in the tube sheet 3 of a first embodiment of the filter asse~bly 1 of Figure 1. In this embodiment, the filter element 4 is slidably inserted from the upper side of the tube sheet 3 through a hole or aperture 11 in t~e tube sheet 3. The open end of the filter element 4 may include a flan~e 12 which prevents the filter element 4 from passing completely through the aperture 11. The flange 12 may be at any suitable angle to an axis 28 of the filter element 4. If the flange is at a right angle, the flange may engage the top of the tube sheet 3 or a lip formed in the wall defining the aperture 11. In the first embodiment, the flange 12 slopeæ upwardly at an acute angle and cooperates with a corresponding locating profile 13, e.g., an annular bevel, in the aperture wall.
In accordance with one aspect of the invention, a sealing device 5 i8 preferably utilized to seal the filter element 4 to the tube sheet 3. In the first embodiment, the ~ealing device 5 also functions as a hold-down element for securing each filter element 4 to the tube sheet 3. The sealing device 5 may be fabricated as a ~ingle unitary piece or from two or more separate sections by, for example, machining, forming, stamping, or casting.
If it is made from two or more separate sections, the sections of the sealing ~evice 5 may be joined together by various methods ~uch as a welded, threaded, or press fit connection. Further, the ~ ~ U~3~
sealing device 5 may be variously configured without departing from the ~cope of the invention. For example, the illustrated sealing device 5, as shown in Figures 3-4, may include a ~lat planar or disk section 15 and a hollow cylindrical section 16 which are unitarily formed. In a preferred embodiment, it may be defiirable for a planar bottom surface of the disk ~ection 15 to have a larger diameter than the ~ cylindrical section ~6 and extend radially out be-¦ 10 yond an outer surface 21 of the hollow cylindrical section 16, forming the bottom annular surface 20.
The sealing device 5 includes an internal passage 19 passing through the device from one open end to another. For example, in the illustrated sealing device 5, the passage 19 extends axially ~ through the hollow cylindrical sectisn 16 and ¦ through the planar surface of the disk section 15.
The configuration of the internal passage 19 may or may not be arranged in such a manner as to act a~ a 20 venturi or nozzle 17. The nozzle 17, or an alterna-tive capillary (jet) configuration, can be used to ~ increase the velocity of fluid flowing in the back ¦ flow direction and, thus, to enhance the blowback effectiveness when the filter elements 4 are cleaned. In an alternative embodiment, it my he preferable for the internal passage 19 to be config-ured as a plurality of internal passages. At least one of th~se plurality of internal passages may be formed into a nozzle, capillary, or jet configura- -tion to provide a means for increasing back flow efficiency. In yet another embodiment, the internal passage may simply be a cylindrical bore.
Chemical corrosion may occur as ~ result of chemicals in the fluids processed through the filter assembly. As a result, the sealing device S is ~;, , . , . . , ................. , . , ~
~', ' ' , , . . . '.' ~'~: ' ' , ; ' ,.'.''. , ~ L U ~ ~ 3 g preferably manufactured from a material which resists corrosion, for example, a high temperature, corrosion resistant, metal alloy such as RA333, available from Rolled Alloys of Temperance, MI.
The sealing device 5 is shown in Figure 2 as it might appear installed in a filter assembly 1.
The sealing device 5 is placed over the top of the filter element 4 with the hollow cylindrical ~ection 1 16 extending for some distance into the internal : lO cavity of the filter element 4. For example, the cylindrical section 16 of the sealing device 5 may '` extend into the internal cavity of the filter f element 4 a distance at least a~ great as the thickness of the tube sheet 3. It may be desirable 15 to position a compressible cu~hioning and/or sealing ~ material 14 between the filter element 4 and the f tube ~heet 3 and/or between the sealing device 5 and I the filter element 4. In a preferred embodiment, ! the compressible material 14 may be a high ~ 20 temperature gasket material, most preferably a ¦ ceramic fiber material such as that available from ¦ 3M Corporation under the trade designation Interam.
i In the illustrated embodiment, the compressible material 14 is disposed between the filter element 4 25 and the tube sheet 3 only at the portion of the tube sheet forming the locating profile 13. Of course, it i8 possible to have the compressible material 14 located over the entire area between the filter element 4 and the tube sheet 3. The openings in the 30 tube sheet 3 may have portions that closely match the profile of the outer portion of the filter ele-ment 4 and, in particular, the flange 12. The comp-ressible material 14 placed between the tube sheet and the filter ele~ent 4 acts to dampen any vibra-35 tion which may be transferred to the filter element _ g _ ~,: . . , - , : , , 3 ~
4 from the pressure tank 2.
In a preferred embodiment, it may be desirable to place the compressible material 14 between the disk section 15 of the sealing device 5 and the top of the filter element 4 as well as between the outside of the hollow cylindrical section 16 of the sealing device 5 and the internal surface of the ~ilter element 4. The compressible material 14 acts as a cushion and/or a sealing gasket. The compres-sible material 14 may also act to prevent uneven ~ stresses from being generated in the filter element i 4 due to non-uniformities on the interacting surfac-~8 of the ~ilter element 4, the sealing device 5, and/or the tube sheet 3. The use of the compress-~ 15 ible material 14 is particularly useful when the I filter element 4 is a ceramic material. A ceramic material has a much lower ductility, i.e., less of an ability to deform under stress before fracture.
~ When two surfaces are in contact, the area of 1 20 contact i8 typically the highest points on the two surfaces. As a compressive force is applied, because of the ductility of the materials in contact, the high points in contact deform and allow a progressively larger portion of the two surfaces to come in contact, thereby reducin~ the stresses at the points of contact. Ceramic has very low ductility and tends to concentrate stresses over the initial contact points. When a compressible I material is used in the interface of two ceramic ! 30 surfaces or a ceramic surface and a metallic surface, the stress distribution is significantly improved. The use of the compressible ma~erial reduces the likelihood of fractures due to this stress.
A preload force may be used to compress the " , . ..
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compressible material 14 between the top of the filter element 4 a~d the bottom annular surface 20 of the hold-down disc section 15. The preload force should preferably be of a magnitude to sufficiently ! 5 compress the compressible material 14 to prevent fluid flow between the bottom surface 20 of the hold-down disc section 15 and the top of the filter ¦ element 4. The preload force may be maintained on the sealing device 5 by securing the sealing device , 10 5 to the tube sheet 3 by any suitable method, in-cluding ~ome type of mechanical method or mechani~m such as welding, bolting, threading, latching, locking, or a pin-and-hole connection. The method of connection should be capable of withstanding vibrations and thermal shock resulting, for example, from pulse cleaning of the filter elements. In the illustrated embodiment, the disk section 15 o~ the sealing device is welded to the tube sheet. The weld further functions as a seal preventing the fluid to be filtered from bypassing the filter element 4.
In accordance with another aspect of the inven-tion, the sealing device 5 and the filter element 4 preferably have different rates of thermal expansion and these different rates of thermal expansion ef-¦ fect a seal between the filter element ~ and the ~ sealing device 5 throughout the entire range of I system temperatures. During start up or shutdown il and at other times, the filter assembly is at rela-tively low temperature and pressure, e.g. atmospher-ic pressure and room temperature. A seal is then preferably maintained between the top of the filter element 4 and the disc section 15 of the sealing device 5 by compression of the compressible material 14 due to the compressive preload placed on the -- 11 -- :
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sealing device 5 during installation.
On the other hand, operating temperature and pressure ~ay be much higher~ For example, the filter assembly 1 may be operated at a temperature oP around 300-C to 1~00C and at a pressure of around 2 to 10 atmospheres. Embodiments of the present invention preferably utilize a sealing device and a filter element 4 having different coef-ficients of thermal expansion and take advantage of 3 lo the different rates of thermal expansion to further seal the filter element 4 to the sealing device at these elevated temperatures. For example, in a preferred embodiment, the sealing device 5 may be constructed from a metal alloy while the filter 15 element 4 may be constructed from a ceramic. Ceram-, ics typically have a ~uch lower coefficient of ther-mal expansion than metals. Thus, as the temperature of the filter assembly 1 is increased during opera-tion, the sealing device 5 may expand at a faster ~ 20 rate than dses the filter element 4 due to the dif-s ferent coefficients of thermal expansion of metals and ceramics.
7 ~he increase in temperature may result in a gradual increase in the relative distance between 25 the top of the filter element 4 and the bottom ~urface 20 of the hold-down disc section 15. This may reduce the compressive force on the compre sible ~5 material 14 between the top of the filter element 4 3 and the bottom surface 20 of the hold-down disc 30 section 15 and, thereby, reduce sealing efficiency.
, However, although the sealing efficiency may be reduced between the top of the filter element 4 and ' the bottom of the hold-down disc section 15, the overall sealing efficiency between the filter 35 element 4 and the sealing device 5 is retained.
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The increase in temperature also results in the hollow cylindrical section 16 of the sealing device 5 expanding radially at a faster rate than the filter element 4. This has the effect of reducing S the clearance between the hollow cylindrical seckion 1 16 and the internal surface of the filter element 4, I thus compressing the compressible material 14 and I sealing the cylindrical section 16 of the sealing device 5 against the internal surface of the filter I 10 ele~ent 4 even tighter. In this way an effective I seal i8 maintained throughout the entire range of system temperatures.
Additionally, an effective seal is maintained even after repeated temperature cycling. Having both a low temperature compressible seal and a high I temperature compressible seal is more reliable than I conventional devices having only a high temperature seal or a low temperature seal. Without the use of both a low temperature seal and a high temperature ~ 20 seal, after repeated temperature cycling, the ¦ compressible material may be over compressed and ~ reduced reliability may result. By having both the ¦ low temperature seal and the high temperature seal, I neither seal is over compressed at any point in the ¦ 25 temperature cycle. The low temperature seal seals at low temperatures, the high temperature seal seals at high temperatures, and an effective seal i~
maintained by both the low and high temperature seals at intermediate temperatures, resulting in increased reliability.
Embodiments of the present invention have the added advantage that the stress from thermal shock and vibration is redistributed to an elongated area along the internal surface of the filter element 4, reducing the stress at the flange. As previously 3 ~
cited, cracking of the flange is a common failure of the filter elements. Embodiments of the present invention can extend into the filter element 4 a ~ignificant distance beyond the flange, even beyond the depth of the tube sheet. In this manner, the stress caused by vibration and thermal shock is distributed over a wider area of the filter element.
In addition, if a crack does occur at the flange, ~ embodiments of the present invention may prevent any 1 10 particulate leakage at operating temperatures since the hollow cylindrical section of the sealing device , provides a seal that can extend below the flange of ¦ the filter element.
A second exemplary filter assembly embodying the present invention is illustrated in Figure 4.
A, (Many of the components of the second embodiment are ~t similar to the component~ of the first embodiment ,~) and are identified by identical reference numerals.J
In this embodiment, the sealing device comprises a j 20 tube sheet 3 having a hollow cylindrical portion 37 located about an aperture 1~ in the tube sheet 3.
While the hollow cylindrical portion may protrude fro~ the lower surface of the tube sheet, in the i illustrated embodiment it protrudes from the upper surface. The hollow cylindrical portion may be joined to the tube sheet by various methods such as a welded, threaded, or press fit connection, or may be ~ormed integral therewith.
The filter element 4 is preferably a ceramic filter, such as a ceramic candle filter, and it may be fabricated according to conventional techniques, uch as molding, isostatic pressing, extrusion, or machining. The filter element 4 has an open end portion which includes a flange 12. The flange 12, in turn, may include an opening such as an annular . ..
n r) 3 groove 23 located above the internal cavity of the ~ filter element 4 with the tube sheet facing the end i portion of the flange 12. While the annular groove may face upwardly in the direction of the open end, j 5 in the illustrated embodi~ent it faces downwardly in the direction of the closed end of the filter element.
The hollow cylindrical portion 37 of the tube sheet engages the annular groove in the filter element 4. A compressible sealing and/or cushioning ~aterial 14 may be disposed anywhere between the tube she2t and the filter element, for example, between an outer cylindrical wall surface 38 of the hollow cylindrical portion 37 and an inner facing I 15 surface 39 of the annular groove 23. ~dditionally, I a compressible sealing and/or cushioning material ¦ may be disposed between a top wall surface 40 of the hollow cylindrical portion 37 and a downward facing sur~ace of the annular groove 23. In this ~0 embodiment, the filter element 4 may be held-down using any suitable mechanism incl~ding the weight of the filter element. Thus, both a high temperature and low temperature seal may be obtained as with the fir~t embodiment. Alternatively, when only a high temperature seal is desired the compressible sealing and/or cushioning material need only be disposed about the outer cylindrical wall surface 38.
~ he sealing device of this second embodiment does not function as a hold-down device.
Conse~uently, a separate hold-down device, for example, a clampinq mechanism such as a hold-down plate, may be coupled to the tube sheet for securing each filter element to the tube sheet and providing a preload force for urging the filter element toward the tube sheet as previously explained with regard ~J Vc~3S
to the first embodiment. However, with the hollow cyli~drical portion 37 protruding upwardly and the annular groove 23 facing downwardly, the weight sf the filter element 4 urges the flange 12 toward the holiow cylindrical portion 37. If the downward gravitational force resulting from the weight of the filter element 4 substantially exceeds any upward force on the filter element 4 created by fluid flowing through the filter assembly, then the hold-down device may not be necessary.
In operation, the second embodiment functionssimilarly to the operation of the first embodiment.
The tube sheet 3 is made of a substance, e.g., a metal such as stainless steel, that e~pands at a higher rate with temperature than the substance, e.g., a ceramic, that the filter element 4 i~ made of. As the temperature rises, the circumference of the hollow cylindrical portion 37 of the tube sheet 3 increases at a higher rate than the circumference of the annular groove 23 of the filter element 4.
Thus, at elevated temperatures, the differing coefficients of thermal expansion between the tube sheet 3 and the filter element 4 cause the compress-ible material 14 to be compressed between the outer cylindrical wall surface 38 of the hollow cylindri- -cal portion 37 and the inner facing surface 39 of the annular groove 23 which faces the internal pas-sage, thereby sealing the filter element to the tube sheet and more evenly distributing stress along the flange of the filter element. This second embodiment has the further advantage that the hollow cylindrical portion 37 is not disposed directly in the fluid flow path and, therefore, is less -`-susceptible to corrosion and can be easily cooled using the same system which is utilized to cool the . , .
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tube sheet 3.
A third emb-odiment of the invention is illus-trated in Figure 5. (Many of the components of the third embodiment are similar to the components of 5 the first embodiments and are id~ntified by identical reference numerals.) In this embodiment, ', the sealing device al~o comprises a tube sheet 3 having a hollow cylindrical portion 37 disposed about an aperture 11 in the tube sheet 3. The 10 hollow cylindrical portion 37 define~ an internal i passage 19 which is coupled to the aperture 11. The Z internal passage 19 may include a means for increasing back flow efficiency as discussed with re~pect to the first embodiment. The tube sheet 3 15 and the hollow cylindrical section 36 may be integrally formed by, for example, machining, , forming, stamping, or casting. If the tube sheet 3 ¦ and hollow cylindrical section 36 are made from two or more separate elements, they may be coupled by 20 various methods such as a welded, threaded, latched, I locked, or press fit connection.
¦ The filter element 4 ha~ an open end which Z includes a flange 12. The hollow cylindrical i portion 37 is capable of being fitted within and Z 25 extending for some distance into the open end of the . filter element 4 with the tube sheet 3 facing the end portion of the filter element 4. The compre~sible material 14 may be disposed anywhere between the tube sheet 3 and the filter element 4, 30 for example, between the inner facing surface of the filter element 4 and an outer cylindrical wall surface 38 of the hollow cylindrical section 37.
In this embodiment, the filter elements 4 may ::
be arranged so that the open end of each filter ele-35 ment 4 is abutting the lower surface of the tube .
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sheet 3. Consequently, it is not necessary to insert the filter elements 4 through the apertures 11 in the tube sheet 3; the filter elements may simply be fitted to the hollow cylindrical portions 37 from the underside of the tube sheet. To secure the filter elements to the tube sheet, a support plate 26 may be coupled to the tube sheet 3 and/or a support grid 22 may be coupled to the pressure tank 2 at the closed ends 27 of the filter elements 4.
The support plate 26 and support grid 22 may be respectively coupled to the tube sheet 3 or bottom surface of the pressure tank 2 by various methods such as a welded, threaded, latched, locked, press fit, or pin-in-hole connection. A compressible sealing and/or cushioning material 14 may be located between the flange 12 of the filter element 4 and the support plate 26 to evenly distribute the load and reduce stress on the flange and/or between the closed end 27 of the filter element support grid 22 to evenly distribute the weight of the filter element 4. The support plate 26 or support grid 22 s may be configured to provide a preload force on the compressible material as previously explained with regard to the first embodiment.
In operation, the third embodiment functions similarly to the first and second embodiments. The tube sheet 3 is made of a substance, e.g., a metal such as stainless steel, that expands at a higher rate with temperature than the substance, e.g., a ceramic, that the filter element 4 is made of. As the temperature rises, the circumference of the hol-low cylindrical section 37 increases at a higher rate than the circumference of the internal surface of the filter element 4. Thus, at elevated tempera-tures, differing coefficients of thermal expansion ' ~ ` .-;. :
rr'.' '' ~ 3 ~
:
between the tube sheet 3 and the filter element 4 cause the compressible material 14 to be compressed between the outer cylindrical wall surface 38 of the hollow cylindrical section 37 and the inner facing 5 surface of the filter element 4. This seals the I filter element to the tube sheet and evenly ¦ distributes stress along the filter element. This i third embodiment has the further advantage that the hollow cylindrical section 37 can be easily cooled 10 using the same system which cools the tube sheet 3.
~ While several exemplary filter assemblies i embodying the present invention have been shown, it ¦ will be understood, of course~ that the invention is ! not limited to these embodiments. Modification may 15 be made by those skilled in the art, particularly in light of the foregoing teaching~. It ic, therefore, ~i intended that the appended claims cover any such modifications which incorporate the features of this invent~on or encompass the true spirit and scope of 20 the invention. For example, the sealing device may be configured in a mirror image in which a hollow aylindrical section may be coupled to both planar surfaces of the disc section or tube sheet. In this f manner, the mirror image configuration may be f 25 utilized to connect two filter elements in a serial ¦ or parallel arrangement. Further, although a cylin-¦ drical shape is preferred, the filter elements and sealing devices illustrated herein are not limited to a cylindrical shape.
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.
-- 19 -- '
In a preferred embodiment, it may be desirable to place the compressible material 14 between the disk section 15 of the sealing device 5 and the top of the filter element 4 as well as between the outside of the hollow cylindrical section 16 of the sealing device 5 and the internal surface of the ~ilter element 4. The compressible material 14 acts as a cushion and/or a sealing gasket. The compres-sible material 14 may also act to prevent uneven ~ stresses from being generated in the filter element i 4 due to non-uniformities on the interacting surfac-~8 of the ~ilter element 4, the sealing device 5, and/or the tube sheet 3. The use of the compress-~ 15 ible material 14 is particularly useful when the I filter element 4 is a ceramic material. A ceramic material has a much lower ductility, i.e., less of an ability to deform under stress before fracture.
~ When two surfaces are in contact, the area of 1 20 contact i8 typically the highest points on the two surfaces. As a compressive force is applied, because of the ductility of the materials in contact, the high points in contact deform and allow a progressively larger portion of the two surfaces to come in contact, thereby reducin~ the stresses at the points of contact. Ceramic has very low ductility and tends to concentrate stresses over the initial contact points. When a compressible I material is used in the interface of two ceramic ! 30 surfaces or a ceramic surface and a metallic surface, the stress distribution is significantly improved. The use of the compressible ma~erial reduces the likelihood of fractures due to this stress.
A preload force may be used to compress the " , . ..
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compressible material 14 between the top of the filter element 4 a~d the bottom annular surface 20 of the hold-down disc section 15. The preload force should preferably be of a magnitude to sufficiently ! 5 compress the compressible material 14 to prevent fluid flow between the bottom surface 20 of the hold-down disc section 15 and the top of the filter ¦ element 4. The preload force may be maintained on the sealing device 5 by securing the sealing device , 10 5 to the tube sheet 3 by any suitable method, in-cluding ~ome type of mechanical method or mechani~m such as welding, bolting, threading, latching, locking, or a pin-and-hole connection. The method of connection should be capable of withstanding vibrations and thermal shock resulting, for example, from pulse cleaning of the filter elements. In the illustrated embodiment, the disk section 15 o~ the sealing device is welded to the tube sheet. The weld further functions as a seal preventing the fluid to be filtered from bypassing the filter element 4.
In accordance with another aspect of the inven-tion, the sealing device 5 and the filter element 4 preferably have different rates of thermal expansion and these different rates of thermal expansion ef-¦ fect a seal between the filter element ~ and the ~ sealing device 5 throughout the entire range of I system temperatures. During start up or shutdown il and at other times, the filter assembly is at rela-tively low temperature and pressure, e.g. atmospher-ic pressure and room temperature. A seal is then preferably maintained between the top of the filter element 4 and the disc section 15 of the sealing device 5 by compression of the compressible material 14 due to the compressive preload placed on the -- 11 -- :
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sealing device 5 during installation.
On the other hand, operating temperature and pressure ~ay be much higher~ For example, the filter assembly 1 may be operated at a temperature oP around 300-C to 1~00C and at a pressure of around 2 to 10 atmospheres. Embodiments of the present invention preferably utilize a sealing device and a filter element 4 having different coef-ficients of thermal expansion and take advantage of 3 lo the different rates of thermal expansion to further seal the filter element 4 to the sealing device at these elevated temperatures. For example, in a preferred embodiment, the sealing device 5 may be constructed from a metal alloy while the filter 15 element 4 may be constructed from a ceramic. Ceram-, ics typically have a ~uch lower coefficient of ther-mal expansion than metals. Thus, as the temperature of the filter assembly 1 is increased during opera-tion, the sealing device 5 may expand at a faster ~ 20 rate than dses the filter element 4 due to the dif-s ferent coefficients of thermal expansion of metals and ceramics.
7 ~he increase in temperature may result in a gradual increase in the relative distance between 25 the top of the filter element 4 and the bottom ~urface 20 of the hold-down disc section 15. This may reduce the compressive force on the compre sible ~5 material 14 between the top of the filter element 4 3 and the bottom surface 20 of the hold-down disc 30 section 15 and, thereby, reduce sealing efficiency.
, However, although the sealing efficiency may be reduced between the top of the filter element 4 and ' the bottom of the hold-down disc section 15, the overall sealing efficiency between the filter 35 element 4 and the sealing device 5 is retained.
.,,, : . -, . . - . :
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The increase in temperature also results in the hollow cylindrical section 16 of the sealing device 5 expanding radially at a faster rate than the filter element 4. This has the effect of reducing S the clearance between the hollow cylindrical seckion 1 16 and the internal surface of the filter element 4, I thus compressing the compressible material 14 and I sealing the cylindrical section 16 of the sealing device 5 against the internal surface of the filter I 10 ele~ent 4 even tighter. In this way an effective I seal i8 maintained throughout the entire range of system temperatures.
Additionally, an effective seal is maintained even after repeated temperature cycling. Having both a low temperature compressible seal and a high I temperature compressible seal is more reliable than I conventional devices having only a high temperature seal or a low temperature seal. Without the use of both a low temperature seal and a high temperature ~ 20 seal, after repeated temperature cycling, the ¦ compressible material may be over compressed and ~ reduced reliability may result. By having both the ¦ low temperature seal and the high temperature seal, I neither seal is over compressed at any point in the ¦ 25 temperature cycle. The low temperature seal seals at low temperatures, the high temperature seal seals at high temperatures, and an effective seal i~
maintained by both the low and high temperature seals at intermediate temperatures, resulting in increased reliability.
Embodiments of the present invention have the added advantage that the stress from thermal shock and vibration is redistributed to an elongated area along the internal surface of the filter element 4, reducing the stress at the flange. As previously 3 ~
cited, cracking of the flange is a common failure of the filter elements. Embodiments of the present invention can extend into the filter element 4 a ~ignificant distance beyond the flange, even beyond the depth of the tube sheet. In this manner, the stress caused by vibration and thermal shock is distributed over a wider area of the filter element.
In addition, if a crack does occur at the flange, ~ embodiments of the present invention may prevent any 1 10 particulate leakage at operating temperatures since the hollow cylindrical section of the sealing device , provides a seal that can extend below the flange of ¦ the filter element.
A second exemplary filter assembly embodying the present invention is illustrated in Figure 4.
A, (Many of the components of the second embodiment are ~t similar to the component~ of the first embodiment ,~) and are identified by identical reference numerals.J
In this embodiment, the sealing device comprises a j 20 tube sheet 3 having a hollow cylindrical portion 37 located about an aperture 1~ in the tube sheet 3.
While the hollow cylindrical portion may protrude fro~ the lower surface of the tube sheet, in the i illustrated embodiment it protrudes from the upper surface. The hollow cylindrical portion may be joined to the tube sheet by various methods such as a welded, threaded, or press fit connection, or may be ~ormed integral therewith.
The filter element 4 is preferably a ceramic filter, such as a ceramic candle filter, and it may be fabricated according to conventional techniques, uch as molding, isostatic pressing, extrusion, or machining. The filter element 4 has an open end portion which includes a flange 12. The flange 12, in turn, may include an opening such as an annular . ..
n r) 3 groove 23 located above the internal cavity of the ~ filter element 4 with the tube sheet facing the end i portion of the flange 12. While the annular groove may face upwardly in the direction of the open end, j 5 in the illustrated embodi~ent it faces downwardly in the direction of the closed end of the filter element.
The hollow cylindrical portion 37 of the tube sheet engages the annular groove in the filter element 4. A compressible sealing and/or cushioning ~aterial 14 may be disposed anywhere between the tube she2t and the filter element, for example, between an outer cylindrical wall surface 38 of the hollow cylindrical portion 37 and an inner facing I 15 surface 39 of the annular groove 23. ~dditionally, I a compressible sealing and/or cushioning material ¦ may be disposed between a top wall surface 40 of the hollow cylindrical portion 37 and a downward facing sur~ace of the annular groove 23. In this ~0 embodiment, the filter element 4 may be held-down using any suitable mechanism incl~ding the weight of the filter element. Thus, both a high temperature and low temperature seal may be obtained as with the fir~t embodiment. Alternatively, when only a high temperature seal is desired the compressible sealing and/or cushioning material need only be disposed about the outer cylindrical wall surface 38.
~ he sealing device of this second embodiment does not function as a hold-down device.
Conse~uently, a separate hold-down device, for example, a clampinq mechanism such as a hold-down plate, may be coupled to the tube sheet for securing each filter element to the tube sheet and providing a preload force for urging the filter element toward the tube sheet as previously explained with regard ~J Vc~3S
to the first embodiment. However, with the hollow cyli~drical portion 37 protruding upwardly and the annular groove 23 facing downwardly, the weight sf the filter element 4 urges the flange 12 toward the holiow cylindrical portion 37. If the downward gravitational force resulting from the weight of the filter element 4 substantially exceeds any upward force on the filter element 4 created by fluid flowing through the filter assembly, then the hold-down device may not be necessary.
In operation, the second embodiment functionssimilarly to the operation of the first embodiment.
The tube sheet 3 is made of a substance, e.g., a metal such as stainless steel, that e~pands at a higher rate with temperature than the substance, e.g., a ceramic, that the filter element 4 i~ made of. As the temperature rises, the circumference of the hollow cylindrical portion 37 of the tube sheet 3 increases at a higher rate than the circumference of the annular groove 23 of the filter element 4.
Thus, at elevated temperatures, the differing coefficients of thermal expansion between the tube sheet 3 and the filter element 4 cause the compress-ible material 14 to be compressed between the outer cylindrical wall surface 38 of the hollow cylindri- -cal portion 37 and the inner facing surface 39 of the annular groove 23 which faces the internal pas-sage, thereby sealing the filter element to the tube sheet and more evenly distributing stress along the flange of the filter element. This second embodiment has the further advantage that the hollow cylindrical portion 37 is not disposed directly in the fluid flow path and, therefore, is less -`-susceptible to corrosion and can be easily cooled using the same system which is utilized to cool the . , .
,; ' - . ' ~ . ~ '' .
~ L i~ ~ ~ 3 ~
tube sheet 3.
A third emb-odiment of the invention is illus-trated in Figure 5. (Many of the components of the third embodiment are similar to the components of 5 the first embodiments and are id~ntified by identical reference numerals.) In this embodiment, ', the sealing device al~o comprises a tube sheet 3 having a hollow cylindrical portion 37 disposed about an aperture 11 in the tube sheet 3. The 10 hollow cylindrical portion 37 define~ an internal i passage 19 which is coupled to the aperture 11. The Z internal passage 19 may include a means for increasing back flow efficiency as discussed with re~pect to the first embodiment. The tube sheet 3 15 and the hollow cylindrical section 36 may be integrally formed by, for example, machining, , forming, stamping, or casting. If the tube sheet 3 ¦ and hollow cylindrical section 36 are made from two or more separate elements, they may be coupled by 20 various methods such as a welded, threaded, latched, I locked, or press fit connection.
¦ The filter element 4 ha~ an open end which Z includes a flange 12. The hollow cylindrical i portion 37 is capable of being fitted within and Z 25 extending for some distance into the open end of the . filter element 4 with the tube sheet 3 facing the end portion of the filter element 4. The compre~sible material 14 may be disposed anywhere between the tube sheet 3 and the filter element 4, 30 for example, between the inner facing surface of the filter element 4 and an outer cylindrical wall surface 38 of the hollow cylindrical section 37.
In this embodiment, the filter elements 4 may ::
be arranged so that the open end of each filter ele-35 ment 4 is abutting the lower surface of the tube .
~, . , -... . . .
" . .
luJ33~
sheet 3. Consequently, it is not necessary to insert the filter elements 4 through the apertures 11 in the tube sheet 3; the filter elements may simply be fitted to the hollow cylindrical portions 37 from the underside of the tube sheet. To secure the filter elements to the tube sheet, a support plate 26 may be coupled to the tube sheet 3 and/or a support grid 22 may be coupled to the pressure tank 2 at the closed ends 27 of the filter elements 4.
The support plate 26 and support grid 22 may be respectively coupled to the tube sheet 3 or bottom surface of the pressure tank 2 by various methods such as a welded, threaded, latched, locked, press fit, or pin-in-hole connection. A compressible sealing and/or cushioning material 14 may be located between the flange 12 of the filter element 4 and the support plate 26 to evenly distribute the load and reduce stress on the flange and/or between the closed end 27 of the filter element support grid 22 to evenly distribute the weight of the filter element 4. The support plate 26 or support grid 22 s may be configured to provide a preload force on the compressible material as previously explained with regard to the first embodiment.
In operation, the third embodiment functions similarly to the first and second embodiments. The tube sheet 3 is made of a substance, e.g., a metal such as stainless steel, that expands at a higher rate with temperature than the substance, e.g., a ceramic, that the filter element 4 is made of. As the temperature rises, the circumference of the hol-low cylindrical section 37 increases at a higher rate than the circumference of the internal surface of the filter element 4. Thus, at elevated tempera-tures, differing coefficients of thermal expansion ' ~ ` .-;. :
rr'.' '' ~ 3 ~
:
between the tube sheet 3 and the filter element 4 cause the compressible material 14 to be compressed between the outer cylindrical wall surface 38 of the hollow cylindrical section 37 and the inner facing 5 surface of the filter element 4. This seals the I filter element to the tube sheet and evenly ¦ distributes stress along the filter element. This i third embodiment has the further advantage that the hollow cylindrical section 37 can be easily cooled 10 using the same system which cools the tube sheet 3.
~ While several exemplary filter assemblies i embodying the present invention have been shown, it ¦ will be understood, of course~ that the invention is ! not limited to these embodiments. Modification may 15 be made by those skilled in the art, particularly in light of the foregoing teaching~. It ic, therefore, ~i intended that the appended claims cover any such modifications which incorporate the features of this invent~on or encompass the true spirit and scope of 20 the invention. For example, the sealing device may be configured in a mirror image in which a hollow aylindrical section may be coupled to both planar surfaces of the disc section or tube sheet. In this f manner, the mirror image configuration may be f 25 utilized to connect two filter elements in a serial ¦ or parallel arrangement. Further, although a cylin-¦ drical shape is preferred, the filter elements and sealing devices illustrated herein are not limited to a cylindrical shape.
' , ~
.
-- 19 -- '
Claims (16)
1. A filter assembly comprising:
a sealing device having first and second surfaces;
a filter element having first and second surfaces respectively disposed about the first surface of the sealing device and adjacent to the second surface of the sealing device; and a compressible material respectively disposed between the first and second surfaces of the filter element and the first and second surfaces of the sealing device, wherein the filter element has a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the sealing device, the compressible material being compressed between the second surfaces at a first predetermined temperature, and the differing coefficients of thermal expansion combine with an increase in temperature of the filter assembly to a second predetermined temperature, higher than the first predetermined temperature, to compress the compressible material between the first surfaces, for forming a seal at both the first and second predetermined temperatures.
a sealing device having first and second surfaces;
a filter element having first and second surfaces respectively disposed about the first surface of the sealing device and adjacent to the second surface of the sealing device; and a compressible material respectively disposed between the first and second surfaces of the filter element and the first and second surfaces of the sealing device, wherein the filter element has a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the sealing device, the compressible material being compressed between the second surfaces at a first predetermined temperature, and the differing coefficients of thermal expansion combine with an increase in temperature of the filter assembly to a second predetermined temperature, higher than the first predetermined temperature, to compress the compressible material between the first surfaces, for forming a seal at both the first and second predetermined temperatures.
2. The filter assembly as claimed in claim 1 wherein the sealing device comprises a metal and the filter element comprises a ceramic.
3. The filter assembly as claimed in claim 1 wherein the first and second surfaces are substantially orthogonal.
4. The filter assembly as claimed in claim 2 wherein the compressible material comprises ceramic fibers.
5. The filter assembly as claimed in claim 1 including:
a tank;
an element disposed within the tank for dividing the tank between an inlet portion and an outlet portion, wherein the sealing device is coupled to the element.
a tank;
an element disposed within the tank for dividing the tank between an inlet portion and an outlet portion, wherein the sealing device is coupled to the element.
6. The filter assembly as claimed in claim 1 wherein the sealing device has a first section having a cylinder-shaped configuration and a second section having a disk-shaped configuration coaxially mounted to the first section, an outer diameter of the first section being less than the outer diameter of the second section.
7. The filter assembly as claimed in claim 1 wherein the body has an internal passage defining a fluid flow path.
8. The filter assembly as claimed in claim 7 wherein the internal passage includes means for increasing back flow efficiency.
9. The filter assembly as claimed in claim 1 wherein the sealing device includes a tube sheet, the filter element being disposed in an aperture in the tube sheet.
10. The filter assembly as claimed in claim 1 wherein the sealing device is disposed within an annular groove within the filter element.
11. The filter assembly as claimed in claim 1 wherein the compressible material being compressed between the second surfaces has a first compressive force at the first predetermined temperature and a second coupressive force, less than the first compressive force, at the second predetermined temperature.
12. The filter assembly device as claimed in claim 1 wherein the sealing device is disposed within an internal cavity within the filter element.
13. A filter assembly comprising:
a filter element having a porous ceramic tube having an open end and a flange including an annular groove; and an annular metal sealing device disposed within the annular groove having a first surface.
a filter element having a porous ceramic tube having an open end and a flange including an annular groove; and an annular metal sealing device disposed within the annular groove having a first surface.
14. T&e filter assembly of claim 13 including a compressible material disposed between the annular metal sealing device and the flange within the annular groove for sealing the flange to the annular metal sealing device.
15. The filter assembly of claim 14 wherein the compressible material is disposed between an outer peripheral side wall of the annular metal sealing device and an inner peripheral side wall of the annular groove for compressing the compressible material at elevated temperatures.
16. The filter assembly as claimed in claim 14 wherein the filter element has a closed end, an open end, and defines an internal cavity therebetween.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/988,642 US5401406A (en) | 1992-12-11 | 1992-12-11 | Filter assembly having a filter element and a sealing device |
| US07/988,642 | 1992-12-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2109536A1 true CA2109536A1 (en) | 1994-06-12 |
Family
ID=25534352
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002109536A Abandoned CA2109536A1 (en) | 1992-12-11 | 1993-11-19 | Filter assembly having a filter element and a sealing device |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US5401406A (en) |
| EP (1) | EP0601733B1 (en) |
| JP (1) | JPH0768106A (en) |
| CA (1) | CA2109536A1 (en) |
| DE (1) | DE69324895T2 (en) |
| FI (1) | FI935540A (en) |
Families Citing this family (43)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6143421A (en) * | 1992-09-17 | 2000-11-07 | Coorstek, Inc. | Electronic components incorporating ceramic-metal composites |
| US6247221B1 (en) * | 1992-09-17 | 2001-06-19 | Coors Tek, Inc. | Method for sealing and/or joining an end of a ceramic filter |
| US5700373A (en) * | 1992-09-17 | 1997-12-23 | Coors Ceramics Company | Method for sealing a filter |
| US6338906B1 (en) | 1992-09-17 | 2002-01-15 | Coorstek, Inc. | Metal-infiltrated ceramic seal |
| US5474586A (en) * | 1994-05-11 | 1995-12-12 | Minnesota Mining And Manufacturing Company | Candle filter assembly and filtration system |
| ES2120300B1 (en) * | 1994-06-15 | 1999-04-01 | Babcock & Wilcox Espanola | PERFECTED FILTER. |
| WO1996002314A1 (en) * | 1994-07-20 | 1996-02-01 | Pall Corporation | A filter assembly having a filter element and a sealing device |
| JP3468436B2 (en) * | 1994-09-22 | 2003-11-17 | 豊田紡織株式会社 | Resin air cleaner |
| US5795359A (en) * | 1994-11-15 | 1998-08-18 | Hosokawa Micron Limited | Apparatus for separating particulate and/or powdery material from an entraining gas |
| DE19715196C2 (en) * | 1997-04-11 | 1999-04-22 | Herding Gmbh | Filter element |
| DE19739510C2 (en) * | 1997-09-09 | 1999-06-24 | Freudenberg Carl Fa | Filter cartridge |
| US5964909A (en) * | 1998-09-04 | 1999-10-12 | Brunner; David | Filter cartridge sealing method |
| US6183529B1 (en) * | 1999-06-01 | 2001-02-06 | Gkn Sinter Metals, Inc. | High temperature gas filter assembly |
| US6302402B1 (en) | 1999-07-07 | 2001-10-16 | Air Products And Chemicals, Inc. | Compliant high temperature seals for dissimilar materials |
| US6468322B1 (en) * | 2000-09-29 | 2002-10-22 | Siemens Westinghouse Power Corporation | Filter holder assembly having extended collar spacer ring |
| DE10063462A1 (en) * | 2000-12-19 | 2002-06-27 | Gkn Sinter Metals Gmbh | Filter candle with a sintered filter tube |
| SE518058C2 (en) * | 2000-12-22 | 2002-08-20 | Alfa Laval Ab | Component for supporting a filter member in a port channel to a plate heat exchanger, device comprising a tubular filter member and said component, and plate heat exchanger comprising a tubular filter member and said component |
| US6547286B1 (en) | 2001-12-27 | 2003-04-15 | Praxair Technology, Inc. | Joint for connecting ceramic element to a tubesheet |
| AU2003226735B2 (en) | 2002-03-26 | 2008-01-10 | Air Products And Chemicals, Inc. | Filter assembly comprising filter elements and a filter grid |
| US20050200124A1 (en) * | 2004-03-12 | 2005-09-15 | Kleefisch Mark S. | High temperature joints for dissimilar materials |
| US20050232834A1 (en) * | 2004-03-30 | 2005-10-20 | Mizan Tahmid I | Mitigation of top of catalyst bed fouling |
| US7291197B2 (en) * | 2004-07-29 | 2007-11-06 | Caterpillar Inc. | Particulate trap filter element |
| DE202007004475U1 (en) * | 2007-03-23 | 2008-08-14 | Volkmann Gmbh | A filter assembly |
| DE202007012178U1 (en) | 2007-08-30 | 2007-10-25 | Rapp, Peter | Filter element with exchangeable filter head |
| JP5020059B2 (en) * | 2007-12-28 | 2012-09-05 | 三菱電機株式会社 | Gas insulated switchgear |
| DE102008014025A1 (en) * | 2008-03-13 | 2009-09-17 | Boehringer Ingelheim Pharma Gmbh & Co. Kg | Inhaler and strainer for an inhaler |
| KR100955944B1 (en) * | 2008-04-16 | 2010-05-04 | 희성정밀 주식회사 | Service Valve for Air Conditioning System |
| DE112009005169B4 (en) | 2009-08-25 | 2013-04-04 | Smc Kabushiki Kaisha | filter |
| US9061251B2 (en) * | 2011-09-27 | 2015-06-23 | Markel Corporation | Self sealing membrane contactor with PTFE tubular membranes |
| US9527022B2 (en) * | 2012-06-08 | 2016-12-27 | Uop Llc | Method and apparatus for producing pyrolysis oil having improved stability |
| JP6026811B2 (en) * | 2012-08-08 | 2016-11-16 | メタウォーター株式会社 | Ceramic filter dust collector |
| US20140158607A1 (en) * | 2012-12-11 | 2014-06-12 | Mahle International Gmbh | Filter with absorbing expansion volume |
| US9039814B2 (en) * | 2013-04-18 | 2015-05-26 | Saes Pure Gas, Inc. | System and method for welding a plurality of small diameter palladium alloy tubes to a common base plate in a space efficient manner |
| KR102055954B1 (en) * | 2013-11-29 | 2019-12-16 | 한국조선해양 주식회사 | Filter apparatus |
| GB2521129B (en) * | 2013-12-10 | 2015-12-09 | Siemens Plc | A current feed-through |
| JP6382613B2 (en) * | 2014-07-18 | 2018-08-29 | 日本特殊陶業株式会社 | Fluid separation device |
| CN104771969B (en) * | 2015-04-20 | 2017-01-11 | 北京京能未来燃气热电有限公司 | Refined filtration drum dedusting device and refined filtration drum dedusting method for inlet air filtering system of gas turbine |
| CN105126491B (en) * | 2015-09-15 | 2017-03-22 | 中国航天空气动力技术研究院 | High-temperature high-pressure fluid cleaning system |
| CN108419412B (en) * | 2018-02-08 | 2020-01-14 | 惠州汉旭五金塑胶科技有限公司 | Water-cooling row with impurity filtering function |
| CN108722060A (en) * | 2018-07-08 | 2018-11-02 | 飞潮（无锡）过滤技术有限公司 | A kind of novel fire resistant ceramic fibre chimney filter |
| EP3980710A4 (en) * | 2019-06-04 | 2023-01-25 | Baltimore Aircoil Company, Inc. | Tubular membrane heat exchanger |
| US11471798B2 (en) * | 2020-11-10 | 2022-10-18 | Regfilter, S.L. | Liquid filtration system |
| US20220362690A1 (en) * | 2021-05-13 | 2022-11-17 | Eaton Intelligent Power Limited | Filter unit with flow optimization |
Family Cites Families (55)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2526651A (en) * | 1945-08-02 | 1950-10-24 | Hydrocarbon Research Inc | Separating powdered catalysts from exothermically reactive gases |
| US2514366A (en) * | 1945-09-19 | 1950-07-11 | Robert W Beyland | Filter |
| US2548875A (en) * | 1947-01-07 | 1951-04-17 | Kellogg M W Co | Contacting gases and solids |
| USRE24954E (en) * | 1951-07-26 | 1961-03-28 | Apparatus for | |
| US3055745A (en) * | 1952-11-07 | 1962-09-25 | Vulcan Cincinnati Inc | Catalytic reactor |
| US2948555A (en) * | 1955-08-08 | 1960-08-09 | Chicago Rawhide Mfg Co | Controlled gap seal |
| US2892510A (en) * | 1957-08-08 | 1959-06-30 | Standard Oil Co | High temperature gas and solids filter |
| DE1507846B2 (en) * | 1965-03-15 | 1977-06-08 | FILTER FOR CLEANING HOT, DUST-CONTAINING GASES | |
| DE1584994B1 (en) * | 1965-12-22 | 1971-03-04 | Schumacher Sche Fabrik | Method and device for the biological purification of waste water |
| US3503516A (en) * | 1968-09-05 | 1970-03-31 | Henry Mfg Co Inc | Pressure filter and tubular filter elements therefor |
| GB1327046A (en) * | 1970-01-28 | 1973-08-15 | Ici Ltd | Filter seal |
| US3642141A (en) * | 1970-07-21 | 1972-02-15 | Per Corp. | Filter tube and connection thereof to tube sheet |
| US3780868A (en) * | 1972-04-19 | 1973-12-25 | Dorr Oliver Inc | Pressure filter having depending tubular filter elements |
| JPS5130220B2 (en) * | 1973-12-11 | 1976-08-30 | ||
| DE2638142A1 (en) * | 1976-05-06 | 1977-11-17 | Textron Inc | FILTER |
| DE2702210C3 (en) * | 1977-01-20 | 1980-10-09 | Schumacher'sche Fabrik Gmbh & Co Kg, 7120 Bietigheim-Bissingen | Filter bodies for the fine separation of mist and solid aerosols from gases, in particular compressed air, as well as processes for the production of such filter bodies |
| CH622134A5 (en) * | 1978-01-25 | 1981-03-13 | Bbc Brown Boveri & Cie | |
| US4336035A (en) * | 1979-03-12 | 1982-06-22 | Wheelabrator-Frye Inc. | Dust collector and filter bags therefor |
| US4461707A (en) * | 1981-10-30 | 1984-07-24 | Canadian Patents & Development Limited | Ultrafiltration and reverse osmosis tubular membrane module |
| US4449422A (en) * | 1982-05-17 | 1984-05-22 | General Motors Corporation | Transmission center support mounting |
| US4522719A (en) * | 1982-12-24 | 1985-06-11 | Nihon Schumacher K.K. | Filter with a tubular filter element |
| US4615261A (en) * | 1984-10-29 | 1986-10-07 | Stirling Thermal Motors, Inc. | Stirling engine with improved piston ring assembly |
| IT1200398B (en) * | 1985-03-04 | 1989-01-18 | L Dolci Spa Ing | FILTERING DEVICE FOR PLASTIC |
| US4673187A (en) * | 1985-07-09 | 1987-06-16 | Fluorocarbon Company | Bimetallic spiral wound gasket |
| JPS6219217A (en) * | 1985-07-17 | 1987-01-28 | Nippon Shiyuumatsuhaa Kk | Filter element in filtration device |
| US4645596A (en) * | 1985-08-26 | 1987-02-24 | Nihon Schumacher Kabushiki Kaisha | Filter apparatus |
| DE3533924A1 (en) * | 1985-09-24 | 1987-06-19 | Schumacher Sche Fab Verwalt | FILTER BODY AND METHOD FOR THE PRODUCTION THEREOF |
| US4725356A (en) * | 1986-02-10 | 1988-02-16 | Industrial Filter & Pump Mfg. Co. | Tubular pressure filter |
| EP0270525B1 (en) * | 1986-05-30 | 1989-08-02 | Schumacher GmbH & Co. KG | Device for filtering gases |
| DE3621726A1 (en) * | 1986-06-28 | 1988-01-14 | Deutsche Forsch Luft Raumfahrt | PISTON PUMP FOR CONVEYING A CRYOGENIC LIQUID |
| US4713174A (en) * | 1986-07-22 | 1987-12-15 | Industrial Filter & Pump Mfg. Co. | Mounting arrangement for a tube-type filter element |
| JPS63116712A (en) * | 1986-10-31 | 1988-05-21 | Nippon Shiyuumatsuhaa Kk | Separating and drying apparatus |
| US4735638A (en) * | 1986-11-18 | 1988-04-05 | The United States Of America As Represented By The United States Department Of Energy | Filter unit for use at high temperatures |
| DE3915845A1 (en) * | 1988-06-04 | 1989-12-14 | Herding Entstaubung | FILTER FOR SEPARATING SOLID PARTICLES FROM HOT, GASEOUS OR LIQUID MEDIA |
| JPH0212421U (en) * | 1988-07-05 | 1990-01-25 | ||
| US4946487A (en) * | 1988-11-14 | 1990-08-07 | Norton Company | High temperature filter |
| US4909813A (en) * | 1989-05-30 | 1990-03-20 | Industrial Filter & Pump Mfg. Co. | Jet pulse extender |
| GB8916839D0 (en) * | 1989-07-22 | 1989-09-06 | Foseco Int | Filters |
| US5037115A (en) * | 1989-09-11 | 1991-08-06 | Brandon Ronald E | Piston ring assemblies for high temperature seals |
| US5037461A (en) * | 1989-09-25 | 1991-08-06 | Industrial Filter & Pump Mfg. Co. | Filtration apparatus |
| US4960448A (en) * | 1989-10-16 | 1990-10-02 | Universal Porosics, Inc. | High temperature gas filter |
| DE3938264A1 (en) * | 1989-11-17 | 1991-05-23 | Babcock Werke Ag | DEVICE FOR FILTERING HOT, DUST-LOADED GASES |
| JPH0647052B2 (en) * | 1989-12-13 | 1994-06-22 | 新日本製鐵株式会社 | Dust filter device |
| DE4007724A1 (en) * | 1990-03-10 | 1991-09-12 | Ernst Apparatebau Gmbh & Co | SOOT FILTER FOR DIESEL ENGINES |
| EP0454346A1 (en) * | 1990-04-21 | 1991-10-30 | United Kingdom Atomic Energy Authority | Exhaust particulate filter |
| DE4017071A1 (en) * | 1990-05-26 | 1991-11-28 | Heimbach Gmbh Thomas Josef | FILTER CANDLE |
| DE9014198U1 (en) * | 1990-10-12 | 1991-03-07 | Thomas Josef Heimbach GmbH & Co, 5160 Düren | Filters, especially hot gas filters |
| US5185019A (en) * | 1990-10-22 | 1993-02-09 | Westinghouse Electric Corp. | Filtering apparatus |
| US5080557A (en) * | 1991-01-14 | 1992-01-14 | General Motors Corporation | Turbine blade shroud assembly |
| US5223138A (en) * | 1991-02-04 | 1993-06-29 | Zievers James F | Reinforced ceramic filter candle and method of making same |
| DE4120920A1 (en) * | 1991-06-25 | 1993-01-07 | Didier Werke Ag | SOOT PARTICLE FILTER |
| US5209844A (en) * | 1991-08-08 | 1993-05-11 | Zievers James F | Hot gas filter with jet pulse cleaning |
| US5202021A (en) * | 1991-08-26 | 1993-04-13 | Hosokawa Micron International Inc. | Integrated molded collar, filter bag, cage and locking ring assembly for baghouses |
| GB2262053B (en) * | 1991-12-03 | 1995-03-08 | Coal Ind | Improvements relating to ceramic candle filter arrangements |
| GB9125714D0 (en) * | 1991-12-03 | 1992-01-29 | Coal Industry Patents Ltd | Improvements relating to candle filter arrangements |
-
1992
- 1992-12-11 US US07/988,642 patent/US5401406A/en not_active Expired - Fee Related
-
1993
- 1993-11-19 CA CA002109536A patent/CA2109536A1/en not_active Abandoned
- 1993-11-22 EP EP93309305A patent/EP0601733B1/en not_active Expired - Lifetime
- 1993-11-22 DE DE69324895T patent/DE69324895T2/en not_active Expired - Fee Related
- 1993-12-10 JP JP5310547A patent/JPH0768106A/en active Pending
- 1993-12-10 FI FI935540A patent/FI935540A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| EP0601733B1 (en) | 1999-05-12 |
| DE69324895D1 (en) | 1999-06-17 |
| JPH0768106A (en) | 1995-03-14 |
| EP0601733A1 (en) | 1994-06-15 |
| DE69324895T2 (en) | 1999-12-09 |
| US5401406A (en) | 1995-03-28 |
| FI935540A0 (en) | 1993-12-10 |
| FI935540A (en) | 1994-06-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |